| 摘要 |
PURPOSE:To ensure normal driving by displaying remaining quantity when the output of a remaining quantity sensor of a fuel tank in a vehicle lies within a predetermined normal region, and displaying abnormality of a fuel gage when the output exceeds the normal region. CONSTITUTION:A fuel sensor is constituted by a contact point 1a which moves up and down in response to the position of a float which is floated on the liquid surface of the fuel. Electrical contact points 2a-2c are connected to the outside. The output is fed to an A/D converter 8 through a circuit comprising resistors 3, 4 and 5, a capacitor 5, and a diode 7. The output of the converter is applied to a microcomputer (CPU)9. When the input lies within the normal region (e.g. 0.4-4.6V) determined by the resistance value and a power supply voltate, the CPU9 computes the remaining quantity. When the input exceeds 10l, the display in ten steps from a full tank is performed. When the input is 10l or less, the display in ten steps in unit of 1l is performed. When the input lies in the region outside said normal region, it is determined that a fault exists in electric circuits or others and the fault is displayed on a display 12. Thus fuel shortage is prevented and the normal driving is ensured. |
